Aerodynamic Studies of High Advance Ratio Rotor Systems

This paper describes ongoing experimental and computational work motivated by increasing interest in high speed rotorcraft. While the long term goal of this activity is to develop improved computational models for high advance ratio rotary wing aerodynamics, a key aspect of work to date has been wind tunnel testing of a simple rotor system at very high μ. These tests have been designed to provide data on rotor performance both guide model development and expand the available validation database for high advance ratios. Key results of recent test entries are described including of rotor lift and drag for advance ratios above 2.0, as well as development of H force data for these conditions. In addition, flow visualization studies using tufted blades were conducted that provided insight into local on-blade flows. Limited validation studies with newly enhanced rotor analysis tools are presented. Finally, goals are outlined for follow-on testing that will address remaining open issues.